SMKDan Diagnostic Bios Garbled and Doesn't Accept Input

neoslacker

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Any ideas? This is an AES 3-6 board.

VRAM has been replaced but actually wasn't bad.

Screen Ram is showing an error under UniBios.

IMG_0529.jpg
 
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neoslacker

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UPDATE: When i hold ABCD, it shows the menu - but the menu shows every thing twice (corrupted). It is sometimes doubled-up in Unibios Menu aswell. Input now works (must have been Joystick problem).

UPDATE : Got through a couple of tests (even with screen corruption)

Got

BRAM DEAD (BAD OUTPUT)
CRASH (reset) when testing 2k VRAM
 

Xian Xi

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This is why making the diagnostic cart helps because it will play the error in tones which is useful when things are scrambled on screen. You just need a CHAR board from any game with an S1 along with the M1 that has the diagnostic code on it.
 

neoslacker

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Don't have a cart I can use right now, but could someone let me know which chip this is? I have replaced the two chips next to the GPU. I still got the same error. Swapping them around I also get the same error.

They are socketed, and before I socketed them, I was getting this error aswell. I checked a LOT of traces coming from those chips and they are all good. Not sure where to go next...

Its the 32k ram test that fails. The palette ram test hangs, with no loops. 2k ram and work ram are fine.
 

GadgetUK

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There are numerous things that could be causing the issue there I think... Have you inspected for broken traces around the LSPC and B1? I wonder about the 74HC259 regards the palette issue and BRAM.
 

neoslacker

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Hey GadgetUK!

Thanks for replying, I was literally just watching your video where you get similar errors (VRAM ADDRESS A0-A7), and I checked all the same traces with a multimeter.

It's weird, I don't see any broken traces, maybe I screwed up the socketing of the CXK5814P, or maybe even the socketing of the Diag Bios (i.e is that's whats causing me to see two menu items for everything).

Is VRAM ADDRESS A0-A7 defintely the CXK5814P?

This is a pic of my actual board

https://www.flickr.com/photos/11357242@N08/43700697425/in/dateposted-public/

I have a 250x microscope, all the right equipment/paste/chipquik etc, also nothing is bridging that i can see,

I've been over it pretty well and and I'm pretty good at soldering SMT but lack some of the AES knowledge to get this going.
 

neoslacker

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Ok, I logic tested the CXK5814P at that screen.

Settings : TTL/PULSE

Here is the result.

HP : High Pulse
L : Low
H : High
LP : Low Pulse
SQ : Square Wave

ram.png

The differences are in RED.

This provide any clues?
 
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neoslacker

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Another Update - I tested the CXK58257AM-10L with the logic tester.

Pin 9 (A1) is floating on the left most ram chip. This pin connects to the other ram chip at Pin 6 (A4) and there is continuity.

The other chip has readings on all pins.

I'm guessing that chip is bad?
 

RyuX

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Here is the LSPC Pinout in regards to the RAM. You can check continuity.

As for the High/Low Levels I am not certain - but it's strange why you get a High on the GND Pin on one chip.

What do you use for Testing the Logic ?

Also all the A Pins should be connected to the same Number on the other RAM Chip... (A1 Chip1 to A1 Chip2, etc.)
Only the I/O Lines should differ as they go to different lines on the LSPC2-A2
 

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GadgetUK

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If the address line is floating - check that it is connected to the LSPC! Could be a broken trace. If it is connected and is still floating - sounds like the LSPC...

EDIT: And A1 on the left RAM should NOT connect to A4 on the other RAM chip... I think the address lines should be in parallel. A1 to A1, A2 to A2, A3 to A3 etc. Databus is not joined between the chips, one is the lower of the 16 bits, the other the upper.
 
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neoslacker

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Actually I tested this with a High/Low logic tester with beeper. I had it set to TTL not CMOS now that I look. When I had it set on CMOS literally everything was Low on like every chip.
 

neoslacker

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Ok - I found the bad trace - it was UNDER the right hand side chip. Repaired the trace and refitted the existing ram. There is continuity now across the pin that was lifted, and looks like no broken traces.

Here was the problem

S20181004_0001.jpg

And under the microscope

S20181004_0004.jpg

Now I have a new problem, The Diag Bios is completely unusable after refitting the ram, and when I use the Universe Bios, the screen is a lot more illegible too. I need to get pics.


Video of UniBios Boot with Game


What I see in Diag with a cart. If bridge some pins on the Ram with a logic tester, it gets a bit more legible, but still cant read anything.

IMG_0539.jpg

Oh also - here is the repair of the pad with Kynar wire. I tested it and its got good continuity up to the pin and isn't bridged.

IMG_0537_(1).jpg

Darn. :( :(
 
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neoslacker

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Anyone know where I could get a spare LSPC chip, or can sell me one, I think that might be the problem.

UPDATE : I snapped a pin off of the LSPC, godammit, I need a donation! halp!
UPDATE : It's Pin D0, it snapped off right up to the casing so I don't think I can solder a wire in. :(
 
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Black IcE

Earl's Long Lost Brother,
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Solid find and fix. I have an AES with ram issues I am working on as well. I will give this a look through on my board as well.
 

neoslacker

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Unfortunately, my LPSC-A02 is toast - have to find a replacement. If anyone can help let me know :-(

Solid find and fix. I have an AES with ram issues I am working on as well. I will give this a look through on my board as well.
 

ack

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Unfortunately, my LPSC-A02 is toast - have to find a replacement. If anyone can help let me know :-(

That chip number doesn't sound correct, you wanna double check? older boards will have LSPC-A0 and newer will have LSPC2-A2.
 

RyuX

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Its easy to snap off a pin on the LSPC2-A2.. happened to me as well.. but I was able to use a cutter knife and cut around the broken off pin and be able to solder a very very thing coil wire to it.
Maybe this will work for you too.. But its a hard process.. Cut with the knife - clean with IPA Alcohol - check with the loupe.. cut again.. etc.
Until you can solder on a wire.. once its soldered on run the wire to the top of the chip and glue it on the top to reduce stress when pulling.

Good luck
 

neoslacker

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Sorry you are right, my bad with the mispelling - its LSPC2-A2, this chip. It's only on AES-3-4 (and upwards) and MV1FZS boards apparently.

That chip number doesn't sound correct, you wanna double check? older boards will have LSPC-A0 and newer will have LSPC2-A2.
 

neoslacker

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Thanks for the tip. It's snapped right up to the edge (2 pins gone), so I'll have to actually cut into the top of the IC to do that, it might be easier to get a used one.

Its easy to snap off a pin on the LSPC2-A2.. happened to me as well.. but I was able to use a cutter knife and cut around the broken off pin and be able to solder a very very thing coil wire to it.
Maybe this will work for you too.. But its a hard process.. Cut with the knife - clean with IPA Alcohol - check with the loupe.. cut again.. etc.
Until you can solder on a wire.. once its soldered on run the wire to the top of the chip and glue it on the top to reduce stress when pulling.

Good luck
 

neoslacker

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UPDATE : ack is helping me out with a parts board! Thanks man. :A:

Here is what happened. The platform holding my repair-work-capture-phone crashed into the board. Cleanup caused pads to lift.

S20181007_0017.jpg

That chip number doesn't sound correct, you wanna double check? older boards will have LSPC-A0 and newer will have LSPC2-A2.
 
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GadgetUK

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Use a dremel to very carefull expose the black plastic just above that pin - if you are super super careful and use a very fine wire, it is entirely possible to expose that pin more and solder a wire. Very hard to do though.
 

neoslacker

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Sounds like a plan. I'll probably do that with it on the board before I remove it to refit the new one. I have a fine Dremel tool, I guess I could also try an exacto knife with the microscope.

Use a dremel to very carefull expose the black plastic just above that pin - if you are super super careful and use a very fine wire, it is entirely possible to expose that pin more and solder a wire. Very hard to do though.
 

neoslacker

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Ok - I managed to get a 0.2mm wire soldered to the edge of one of the 3 broken pins, so I know it's possible. If i can hack out some of the plastic I can make a solid connection. I'll upload some video of this so people can see how I went about this.

Sounds like a plan. I'll probably do that with it on the board before I remove it to refit the new one. I have a fine Dremel tool, I guess I could also try an exacto knife with the microscope.
 
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