LC TDK 699-0153 PSU Reference

[SuperSVGA]

LC TDK 699-0153 PSU​

Since there doesn't seem to be a lot of information on these LC power supplies, I thought I would share what I've been working on the past few months.

My next goal is figuring out what everything on the board does in order to ease diagnosis, unfortunately I don't know much about SMPS or EE in general, so if anyone has any insights feel free to share. I vaguely understand what's going on but not enough to determine how specific voltages are sourced.
Also if anyone can determine the specs of the two transformers, let me know.

Board Components​

All the components on the board, with whatever specs I could determine. I wasn't able to identify most of the diodes.

Spoiler: Board Components

Capacitors​

Loc​	Capacitance​	Voltage​	Type​	Temp​	Lead​	Height​	Diameter​
C1	0.22uF	250V	X1 Safety		23.5mm	19.7mm	24.9mm
C2	0.1uF	250V	X1 Safety		22.9mm	16mm	24.6mm
C3	3.3nF	400V	Ceramic Safety		7.2mm	14.7mm	13.4mm
C4	3.3nF	400V	Ceramic Safety		7.2mm	14.7mm	13.4mm
C5	180uF	385V	Electrolytic	85°C	10.5mm	25mm	30mm
C6	0.01uF	630V	Metal Film				12mm
C8	8.2uF	50V	Electrolytic	105°C	5.15mm	10.8mm	5.25mm
C9	0.001uF		Polyester Film				4.5mm
C10	0.047uF	50V	Polyester Film				6.7mm
C11	3.3nF		Polyester Film				4.5mm
C12	3.3nF	400V	Ceramic Safety		7.2mm	14.7mm	13.4mm
C13	3.3nF	400V	Ceramic Safety		7.2mm	14.7mm	13.4mm
C14	0.01uF		Polyester Film			6mm	5mm
C51	1000uF	10V	Electrolytic	105°C	5.25mm	21.9mm	10mm
C52	1000uF	10V	Electrolytic	105°C	5.25mm	21.9mm	10mm
C53	270uF	25V	Electrolytic	105°C	3.8mm	19.9mm	8mm
C54	270uF	25V	Electrolytic	105°C	3.8mm	19.9mm	8mm
C55	1000uF	10V	Electrolytic	105°C	5.25mm	21.9mm	10mm
C56	56uF	25V	Electrolytic		3mm		4.8mm
C57	0.1uF	63V	Metal Film
C60	47uF	25V	Electrolytic	105°C	4.7mm
C61	0.001uF	250V	Polyester Film
C62	0.22uF	63V	Metal Film				8.7mm
C64	270uF	10V	Electrolytic
C66	0.001uF	250V	Polyester Film

Resistors​

Loc​	Resistance​	Power​	Tolerance​
R1	1MΩ	1/4W (250mW)	±5%
R3	150KΩ	1/2W (500mW)	±5%
R4	150KΩ	1/2W (500mW)	±5%
R5	120KΩ	1/2W (500mW)	±5%
R6	39Ω	1/8W (125mW)	±5%
R7	120KΩ	1/8W (125mW)	±5%
R8	13KΩ	1/8W (125mW)	±1%
R9	5.6KΩ	1/8W (125mW)	±1%
R10	260Ω	1/8W (125mW)	±5%
R11	120Ω	1/8W (125mW)	±5%
R12	0.22Ω	1/2W (500mW)	±5%
R13	120Ω	1/8W (125mW)	±5%
R14	150KΩ	1/8W (125mW)	±5%
R15	0.22Ω	1/2W (500mW)	±5%
R16	10KΩ	1/8W (125mW)	±5%
R51	27Ω	1/2W (500mW)	±5%
R54	460Ω	1/8W (125mW)	±5%
R57	10KΩ	1/8W (125mW)	±5%
R58	22Ω	1/8W (125mW)	±5%
R59	6.8Ω	1/8W (125mW)	±5%
R61	12KΩ	1/8W (125mW)	±1%
R62	2.2KΩ	1/8W (125mW)	±5%
R63	220KΩ	1/4W (250mW)	±5%
R64	100Ω	1/4W (250mW)	±5%
R66	2.2KΩ	1/8W (125mW)	±5%

Diodes​

Loc​	Identifier​	Type​
CR1	KBP06M 3N250	Bridge Rectifier
CR2
CR3	2 2G 1DF
CR4	24B	Zener
CR5	62B	Zener
CR51	C82M	Barrier Diode
CR52	B82M	Barrier Diode
CR53	2 2G 1DF
CR54		Zener
CR55		Zener
CR56		Zener
CR57	2 2G 1DF

Other Components​

Loc​	Name​	Identifier​
F1	2A 250V T2A
IC1	Power IC	M51996P
IC51	Voltage Regulator	C78N05
IC53	Optocoupler	Sharp PC111
IC54	Shunt Regulator	HA17431P
IC55	Thyristor	NEC 8P2
L1	Power Choke?	290A P27
L51	Inductor - 2.2uH	2R2M
L52	Inductor - 4.7uH	4R7M
L53	Inductor - 2.4uH?
Q1	MOSFET	K1024
R2	Thermistor	16D-9
R56	Potentiometer	202
T1	Transformer	TDK MT1311 M92411
T51	Transformer	T29 MX
	24AWG Solid Wire
	5 Pin LC Power

Unpopulated Board Photos​

Images of the board with all the components removed.

Spoiler: Unpopulated Board Photos

Populated Board Photo​

A picture of a fully populated board, with replaced secondary capacitors.

Spoiler: Populated Board Photo

Redrawn Board Photos​

The PCB redrawn, mostly accurate.
Gerber files are also attached in the post.

Spoiler: Redrawn Board Photos

Board Schematic​

A rough schematic of the board. Hopefully it's somewhat readable.

Spoiler: Board Schematic

 

[EffingController]

Thank you so much for this. I recently obtained an LCIII. I recapped the power supply but I'm getting low voltage on the -5V rail. Hopefully this helps me track down the problem!

 

[SuperSVGA]

Correction to resistor R10, I believe it's actually supposed to be a 27KΩ resistor. I guess the first board I was looking at was discolored a bit.
Also R54 should be 470Ω, not 460Ω

 

[devius]

This is great! I also recently drew the schematic for a TDK PSU, but it’s part number 614-0003. Seems similar enough to this one though. I can share it as well if there’s interest.

 

[dan.dem]

Thank you SuperSVGA this is a great step to successful repairs of the LC power supplies! While replacing the PS with a modern one is feasible, keeping the original ones working feels more satisfying to me.

Please, can someone try to explain the function of the circuitry? This may hint about the missing component specs.
My own knowledge is more (i.e. less) than rusty.
Anyway, I would like to start discussing the schematic myself, even if there are more questions marks than useful information. Probably it provokes some, very welcome, corrections.

Starting with the two fuses U1 and U2, I can only guess one is quicker.
Then I see a filter consisting of C1, a double choke L1, and C2.
?? R1 makes sure, there is always a minimal load on the input circuit, and slightly dampens the CLC-filter??
C3 and C4 are actual in series and ?? make the mains voltage symmetrical to the device ground ??
CR1 is KBP06G, a 600V 1.5 A bridge rectifier.

Probably, someone more competent may take over. Thank you!

 

[SuperSVGA]

Starting with the two fuses U1 and U2, I can only guess one is quicker.

I probably should have made that more clear, there's only one fuse, but the holder is two parts making the symbol two sections.

 

[dan.dem]

I probably should have made that more clear, there's only one fuse, but the holder is two parts making the symbol two sections.

Oh, sorry, I misread this.
Anyway, my hope is that a better understanding of the circuitry leads to recommended procedures for error tracing and repair.
This PS isn't a too complicated, and doesn't need very expensive equipment to repair - like a logic board does.

My hope is we can build up some competence here necessary for reviving classic Mac's PS.

 

[Bit-Worker]

Hi Everybody!

I have just gotten an LC II with a dead power supply, none of the voltages are right, they are mostly around 1-2V, nowhere near what they should, and I would like to attempt to repair.
I never had Mac LCs before, but this PSU is so cute and pretty simple, its amazing!

Thanks *SuperSVGA* for posting this info! It's priceless!

And sharing this info, to be able to fix old gear, does more for the planet than charging for grocery plastic bags...

 

[Mauk]

Hello there
I have an old LC (32 years old) and am trying to repair the PSU at the moment.
Hopefully all goes well

 

[Phipli]

Pretty seriously covered here, but since I've already collected the data and also recorded the series and make (series only for the Nichicons), I'll post it and my "map" here.

 

[Phipli]

Pretty seriously covered here, but since I've already collected the data and also recorded the series and make (series only for the Nichicons), I'll post it and my "map" here.

View attachment 59952View attachment 59949

The ELNA caps are "RSG". Ironically labelled "long life" given they're the ones that have failed.

 

[bnilsson]

I have a Mac LC from mid 90's, I am trying to revive it.

The TDK PS was dead to start, came to life after a few hours (as old electrolytic capacitors sometimes do).
Then it suddenly died again.
I read this thread with great interest.

Replaced all electrolytic caps, the PC came back to life but died again.
Overvoltage 14V/6V or nothing (tick-tick) dependent on the trimmer pot setting.
Replaced the optocoupler. No good.
Replaced the shunt regulator. No good.

Looking at the PCB, it looked strange and icky.
I rinsed the PCB in isopropanol a few times, the liquid in the bucket became severely yellow.
I wiped it off and let it dry.

Started the PS, now it worked perfectly.

The old capacitors had leaked their electrolyte onto a thick layer on the PCB, shorting out all control circuitry.

Lesson learned.

BN

 

[lostone]

Has anyone found a modern equivalent of the C78N05 (IC51)? I've got the unstable -5V output after recapping (and looks like there may be electrolyte or something else on the board, cleaning has been in progress next would be depop and clean or ultrasonic. But before doing that I started looking at components to understand if something isn't working.

I wasn't able to find the TDK MT1311 pinout and while there's a schematic above, I'm not clear what transformer output voltages should be feeding the C78N05. I can see the transformer has 2 inputs and 3 outputs so could throw low voltage AC on the inputs and measure the outputs unless someone else has already done that fun work.
I also question if the C78N05 pin labels in the schematic are correct. Pin 2 is wired directly to the -5V output, so shouldn't that be output not input? I also wonder about transformer p6 being connected to C78N05 pin 2 not pin 1 as shown in the IC51 connections. Looks like transformer pin 5 is connected to pin 1 of C78N05 via the CR(diode). At least that's what my board looks like

7805 (not with the C prefix and N) had different wiring 1: input, 2: ground, 3: output. which this board would be wired similar to how you'd wire a positive regulator for negative output.

The board appears to have this wiring:
1: to the transformer pin5 via the diode labeled CR53 (at least it looks and tests like a .5V diode)
2: to -5V output and transformer pin 6
3: to Ground

If I test with the configuration in the schematic pin out I get .4V on the output, but if I wire up with the standard 7805 with 9V on pin 1 wiring I get -4V on the output with Vin 9V, 10V gets me -5V out.

I found the Panasonic AN79N05 which at least has an N in the part number. I also noticed the Astec version of this supply uses a AN79N05. The 7900 is basically the negative output version of the 7800 regulator.

What isn't clear is if the C and N characters in the C78N05 indicate anything. I suspect the C may just be a manufacturer label, but is the N important? Maybe Negative, maybe internal construction (NPN)? I don't know.

Does anyone have specs on the transformer to check it's not internally shorted? I measured resistances and can see nothing's internally open, and appears to be 3 output wired together in groups of 2 (p1/2, p3/4, and p5/6 with schematic labels). Ground appears to be directly connected to p3 and not a CT with other pins. I know those are just two ends of each coil and how they get used depends on how the circuit is wired.

I also had to the joy of accidently removing a pad while removing components so I get to enjoy some pad repair in this process. Luckily I will fully embrace the chance at something I enjoy. at least with these larger pads it can be fun!

 

[SuperSVGA]

Has anyone found a modern equivalent of the C78N05 (IC51)?

I think something like the ST L7805ABV may work. Not all 7805s are quite the same and I don't remember what qualities are typically required, but the L7805ABV at least shows an example of it being used for negative voltage:

I also question if the C78N05 pin labels in the schematic are correct. Pin 2 is wired directly to the -5V output, so shouldn't that be output not input?

I think the numbering may be incorrect on the schematic symbol, but the labels should be correct. It's been a while so I don't remember what library or part that symbol came from, I may have had to adapt it a few times and that messed up the numbering.

 

[ben68k]

Hi,

Excellent work with the schematic. I have been working on one of these. Would someone with a working supply be able to measure the vcc voltage to the M51996P so I know what it should be? On mine I am getting about 40v. But the spec sheet for that chip says max vcc is around 30v. But when I look at the schematic and manually calculate based on resistor voltage divider from KBP06G output to pin 14 it calculates out to around 40v. How can this be? I am clearly missing something here.

Thank you all

ben

 

[ben68k]

Hi,

Excellent work with the schematic. I have been working on one of these. Would someone with a working supply be able to measure the vcc voltage to the M51996P so I know what it should be? On mine I am getting about 40v. But the spec sheet for that chip says max vcc is around 30v. But when I look at the schematic and manually calculate based on resistor voltage divider from KBP06G output to pin 14 it calculates out to around 40v. How can this be? I am clearly missing something here.

Thank you all

ben

Ok, so, maybe never mind; maybe I figured out my confusion. I was calculating everything from a dc static point of view and forgetting to take into account the dynamics of the startup time of the control chip. I think it all makes sense now.
thank you
ben

 

[lostone]

@ben68k since you're actively digging around in the circuit, could you do me a favor and check the voltages on the C78N05 (IC51). I can't figure out the input voltage (pin1), (with pins numbers 1, 2. 3 when looking at the label side). As noted a couple posts early I am unsure questions about the schematic labels/signals and my -5V is totally unstable and trying to figure out if that's regulating correctly. When I test with a DC supply as a negative regulator my output varies with the input voltage and I thought that should be constant over a wide input voltage range. Thanks if you can.

 

[bnys]

This may be a basic question but how do the colors on the wires correspond the different rails on this PSU? I assume black is GND, but what are yellow, orange, and blue? I have this PSU but it's completely dead and I have no way to measure them right now.

 

[cheesestraws]

This may be a basic question but how do the colors on the wires correspond the different rails on this PSU? I assume black is GND, but what are yellow, orange, and blue? I have this PSU but it's completely dead and I have no way to measure them right now.

You probably want this page: https://old.pinouts.ru/Power/mac_lc_power_pinout.shtml

 

[lostone]

This may be a basic question but how do the colors on the wires correspond the different rails on this PSU? I assume black is GND, but what are yellow, orange, and blue? I have this PSU but it's completely dead and I have no way to measure them right now.

One of several nice things about the Astec AA16-251 version of this supply (which also needed a restore after the two 120uF caps C17 and C20 were found to have 0 capactiance) is the wires are soldered directly into the board with silkscreens! Orange: +5, Yellow: +12, and Blue: -5. This is also the same connector found on the IIGS which also included -12V on a green wire at the unused pin 6 between yellow and blue wires. FWIW, this voltage color scheme has been a constant since the original Apple II.