Quadra 610

[iigs123]

I have a Quadra 610 I'm trying to restore. Many of the original capacitors fell off, so I've replaced all 10 of them. There was some minor surface goo around two of the capacitors. Around C50 - the 74F245 - had some crud on it but it came clean. The legs are intact and seem to be OK now.

With nothing connected - no RAM, no VRAM, no floppy, no SCSI, no keyboard, no monitor, but with a new PRAM battery I tried to power it on. The speaker has a slight pop, the PSU fan spins and the light is on, but there is no chime and no video. When a keyboard is connected the 3 lights briefly light and go out. Caps lock & num lock do not toggle on the keyboard.

Visually not else looks bad. The board looks clean, nothing seems loose.

What else should I check or attempt?

 

[Phipli]

I have a Quadra 610 I'm trying to restore. Many of the original capacitors fell off, so I've replaced all 10 of them. There was some minor surface goo around two of the capacitors. Around C50 - the 74F245 - had some crud on it but it came clean. The legs are intact and seem to be OK now.

With nothing connected - no RAM, no VRAM, no floppy, no SCSI, no keyboard, no monitor, but with a new PRAM battery I tried to power it on. The speaker has a slight pop, the PSU fan spins and the light is on, but there is no chime and no video. When a keyboard is connected the 3 lights briefly light and go out. Caps lock & num lock do not toggle on the keyboard.

Visually not else looks bad. The board looks clean, nothing seems loose.

What else should I check or attempt?

It won't do much at all without video RAM. Fit that and see what happens.

 

[Phipli]

Note you have to fit two VRAM SIMMs. It won't work with one.

You probably want to put a new battery in it too - similar machines won't initialise video without a battery, but should chime (once you fit VRAM).

 

[ymk]

It won't do much at all without video RAM. Fit that and see what happens.

The Centris 610 has onboard VRAM. Is the Quadra different?

 

[Phipli]

The Centris 610 has onboard VRAM. Is the Quadra different?

My bad sorry, I forgot it did.

In that case, good, high resolution photos are probably what we need from @iigs123

 

[iigs123]

The battery is new and has the correct voltage. I've also tried with and without VRAM. It should have onboard VRAM and RAM.

Here is the top of the motherboard. I can take a closer picture of an area if needed.

Thank you!

 

[Phipli]

The battery is new and has the correct voltage. I've also tried with and without VRAM. It should have onboard VRAM and RAM.

Here is the top of the motherboard. I can take a closer picture of an area if needed.

Thank you!


View attachment 58014

Did you take care not to short vias under the Caps? I think it is C53 that has a via right next to one of its pads, I had to solder it off to one side so the bigger pad on the tantalum wasn't in contact.

Check the chip to the right of the CPU in the photo very carefully. That chip is very often a problem. Specifically the top right corner. The nearby capacitor is very good at loosening pins. Happened to me and to @mg.man

 

[Phipli]

I'm going to sleep soon so a few things are...

Does the processor get warm at all when power is applied? If it doesn't, it isn't running, so doesn't have either clock or power, or both.

If it does get warm, have you plugged in a monitor? Perhaps just your sound doesn't work? (Your first post seems to say you didn't plug in a monitor, but also that you don't have video output, which is confusing).

If it doesn't, check the voltages on the power connector. How do the clocks look? Are you able to test if G5 is working? (Next to the CPU).

Are any chips getting abnormally hot?

How did you clean the board? Have you washed it in IPA?

How did you dry the board? You need to make sure there is no water under any chips.

 

[iigs123]

I double checked C53, and it seems to be OK. I also checked the VLSI chip next to the CPU. I didn't notice any shorts or corrosion when looking at it under my "toy" USB microscope.

I cleaned everything with 99% IPA, let dry and also used air to blow out anything under chips. I did not soak the board - it was spot cleaning only.

I did plug in a monitor and keyboard. The speaker is plugged in and has a slight pop when pressing the power button. I don't see anything on the monitor. I'm using a VGA adapter with dip switches, and I tried a few combinations to see if anything came up but nothing did.

I believe the voltages on the PSU are OK, but if someone could confirm the correct values I'd appreciate it. Visually the PSU doesn't have any leaking caps or anything.

The CPU is getting warm. No other chips are abnormally warm.

How might I test G5?

Thank you everyone for the advice.

 

[Phipli]

How might I test G5?

If the cpu is warm you don't need to test G5. Its working.

 

[Phipli]

I believe the voltages on the PSU are OK, but if someone could confirm the correct values I'd appreciate it. Visually the PSU doesn't have any leaking caps or anything.

Someone please correct me if I have 12 and -12 backwards, but conventionally, yellow is 12v.

You can get a probe down the back, but if the CPU is warm that means 5V is working and I'd expect the machine to start booting and video to work at least with only 5v.

I suggest doing some more thorough cleaning with IPS and a non static brush if possible. Basically... a toothbrush, but.. i have a special non static one... I don't want to say "you'll probably be ok with a regular toothbrush" in case you're not. But I do feel like static is less of an issue when you're in a pool of IPA. Physicist opinion needed for input here.

Can I see a photo of your VGA adapter? Both sides and its instructions?

The next thing to check is for shorts or bad connections on each of your caps. Did it work before you recapped?

The behavior is like the computer can't read its ROM for some reason, so I'd start there.

The audio "pop" is the audio circuit being reset. That is a good sign, but it would be better if it then chimed straight afterwards! I believe the pop is from the electrical reset and is not triggered by ROM code, so it just means at least some of the circuit is correctly resetting at power on.

 

[Phipli]

PS, I have a 610 board sat on the side so let me know if there are any continuity tests you want me to compare with yours.

 

[Phipli]

There is a remote chance G1 is playing up...

Very very carefully measure the voltage on this pin :



Is it 0v, 5v or inbetween?

It actually should be a square wave, so ideally, you meter will complain it is unstable and show a voltage between 0 and 5v, in the middleish perhaps. Not exactly the right way of testing this, but should inform if it is running or stuck.

 

[Phipli]

Here is the top of the motherboard. I can take a closer picture of an area if needed.

Photos of the highlighted areas would be potentially interesting.

 

[Phipli]

with IPS and a non static brus

*IPA - phone typo

 

[iigs123]

The PSU has solid 5v and 12v. The neg is -12.25.

G1 measures a consistent 2.2V on that pin which seems middle-ish?

I bought this adapter:

https://www.amazon.com/gp/product/B0016OC1J2/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

I would expect some signal to at least say "out of range" on my NEC 1700M+ with some combination of the DIP but I don't see anything. I can send a pic of it and the instructions soon. Sigh, I wish I would have kept my adapter from 1997... along with the 6500/300 I had at the time.

I'll clean and inspect more today.

Does anyone have a recommendation for a microscope/camera that might be better than the very inexpensive handheld USB one I have now? Maybe one that would do double duty for my kids to inspect things as well? Or, any other tools? I have to say the Hakko soldering iron I bought at Microcenter made a huge improvement over my old cheap iron. Having quick, consistent heat is wonderful.

 

[iigs123]

I forgot to add: the board was believed to be working before I got it. At least one cap was missing when I got it so I never tried to power it on before doing the recap. 8 of the remaining 9 fell of with a gentle tap. Only one had to be desoldered.

 

[Phipli]

I would expect some signal to at least say "out of range" on my NEC 1700M+ with some combination of the DIP but I don't see anything. I can send a pic of it and the instructions soon. Sigh, I wish I would have kept my adapter from 1997... along with the 6500/300 I had at the time.

Not really, you can do lots of wrong settings that result in nothing.

I can't remember which 'mode' you need, so try...

235, 2356, 237, 236, 2367 and 23... sorry for the list, I can't find my 10 switch adapter to test.

At least one of those will work.

 

[Phipli]

Does anyone have a recommendation for a microscope/camera that might be better than the very inexpensive handheld USB one I have now? Maybe one that would do double duty for my kids to inspect things as well? Or, any other tools?

To be honest, a zoomed smartphone camera is as good or better than any of the cheaper microscopes in good light. I don't use a microscope, although, if you have a phone with a single lens, the clip on microscopes are better than expected.

 

[Phipli]

My phone camera :