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5 boards to have a crack at

your a wealth of info man. 6 layers!!!! .........ill stick with macs. Got my hands on an IBM AS/400 the otherday....had a look at the main board......I think its just 2 layers...........but man its just a monster. 10 inch floppy drive (I think)

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anyway good news..........just got a chime from the second se30........a good chime.........but video=1 line across middle of screen. This is the board with the ue8 ripped off.

replaced it with one from one of my dead se30's along with 2 crystals, uj3 (that was on first se30!!), 2 transistors and a few caps.

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have a good se30 alongside this one and im metering away at random - good board , pin 1 to anywhere I can find a beep.... then do same continuioty test on bad ue8

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its 3:36am here in Ireland and im not going to bed until this dam thing works

 
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The line in the screen means your missing vertical drive. it comes from the PAL/GALs I think. have to follow the schematic. 

 
id say its safe to say its ue8..............10 of its pads are gone............along with their traces

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have most of them reconnected

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now I have a broken white line................

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I have 4 pins left to connect

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luckily allot of the pads had via's close by. Melt in a bit of wire (cap leg), bend it to the pin of the chip and solder

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its ugly but its worked before................but never this bad

1.JPG

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3.JPG

 
brave......no

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dumb......... yes

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im doing it for free.

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ahh just pitied the poor guy so said I TRY help out

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that's enough for 1 day

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more havoc to reek tomorow

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good luck lads

 
For what it's worth I recapped an SE/30 recently with a horizontal line on screen-- no change after recap. The culprit turned out to be a via near UF8.

IMG_2487.jpg

From the schematic, UF8 appears to count vertical lines. The output goes to PAL UG6 which probably implements comparators at 342 and 370 lines to generate the VSYNC pulse. Bad connection from UF8 = no match on the comparator = no VSYNC pulse, I think.

Half-baked idea based on the above: UG7 looks to do something similar for HSYNC. Change the comparators on these two (by lifting VSYNC and HSYNC off the PALs or swapping data lines around) to get larger horizontal and vertical resolution. Then overclock to get back to 22.25kHz horizontal scan rate, though either lower vertical refresh or non-square pixels. :)

Probably the video memory would be the downfall of that plan though-- not sure it would be big enough. And beyond that, there would be ROM changes to teach the new resolution....

 
thanks apm...........tested all vias to pins for continuity - they all check out.

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this board seems not to have any acid leak, and very little electrolyte damage.

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the main problem is/was.......(and prob always will be) ue8

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decided to start from scratch today. So removed all caps, ue8 and the pins from the cap legs I used last night

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cleaned board

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used very small wires to melt into via's around ue8 and then to solder onto ue8 legs/pins.

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many pads and traces gone so hade to use wire

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my problem (among others) is I just used basic continuity test on each pin on a good board to find any point where that pin would connect.

applied this to bad board

and soldered in the wires accordingly

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still no joy

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heres a few pics of where the board is, plus a short vid of what happens when I turn it on

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and I know the wires are too dam big.............there all I could fine

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weh hey!

1.JPG

2.JPG

3.JPG

4.JPG

 
the ue8 I am using was from a dead machine - are all these chips the same or is there different versions of a UE8 chip or does the big chunk of UE8 that I knocked off kinda upset the whole show?

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cleaned ron and ram simms (I have 4 in it) with a rubber. Reseated the video memory chip

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I removed UD8 during the cleaning to make sure the torn traces were not touching under the UD8.............they were not. When I went to put it back there was no writing on the chip to orientate it.......so I think I put it back the right way

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helllppppppppppp

 
I dont see the video?? 

Nevermind, I just went to your channel and looked at the last uploaded video. Simple enough. 

 
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You would be better off replacing those chips with new. I have a stash I ordered from digikey to do it. They are all the same. Well sorta. 

There are HC, HCT, AS, F, variants, all with different speeds and voltage ratings. But otherwise thats about it. 

In your neck of the woods, maybe Farnell carries them. 

 
don't know why my vids only show when you click on 'show all content' on the bottom of the screen techknight.

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I have metered out all the connections and they are not shorting. they are all the same as the good board. But I am not using the schematic.

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you say replace those chips.... as in all the video chips UA8 up to UG8...as in all 7 of them

I have another dead se30 ( I have 3 in total) and the ue8 has the numbers tif022 cr   ls166a. All 7 are there... as in 1 set.

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change them all?

 
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No... You want to replace UE8 with a brand new one, trust me. 

With the horizontal line cutting in and out is a for sure bad connection, But replacing UE8 with a brand spanking new SN74LS166 would remove this factor out of the equation, so you dont have to keep mucking with it. 

 
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we wouldn't have anything like that in Ireland techknight.

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believe me this is one crap country for getting specific stuff. Everything is got online. So is a SN74LS166 some kind of generic chip that will definitely work as a UE8

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been at this dam thing 4 hours now so feck it im off to bed. Gigging for the weekend so will have a stab at it on monday

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cheers peoplez

 
A question.

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can an se/30 "single horizontal line" be caused by just UE8.?..........or can it be cause by any of the Ux8 chips (7 of them I think).....or anything else??

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Display is perfect when I install my good board.

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I have  worked on the Ux8 chips, replaces the the FUJ2 258 chip, replaced both transistors next battery and crystal next battery - those parts were missing

Im running out of options

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cheers people

 
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