avatar_keropi

Accidentally used a 9v PSU on the 6128 plus, what's the damage?

Started by keropi, 22:39, 16 June 16

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TFM

Quote from: Bryce on 17:29, 17 June 16
Everybody knows that Bielefeld doesn't exist, but since when has it moved to Ireland???

Bryce.


Look at the chips.  ;)
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

gerald

Quote from: keropi on 09:49, 17 June 16
I already found the auction for me, the one you linked Bryce has +12eur shipping cost to Greece...
KM41464AP-12 64Kx4bit MOS DRAM DIP 18 1PC | eBay


I removed all ram, powered on and I don't get any IC with high temps. The only one that gets slightly warm (maybe 18~20 degrees? one just feels a really slight warmth when touching it) is the large asic. The screen I get now is the following with rolling garbage:





I'd love to have some ram atm for testing - even with some patching but unfortunately I can't find any suitable. I am really curious whether the machine survived or not .

Have you checked the removed RAM 2 by 2 in the 1st bank socket (IC110 / IC111)?
With a bit of luck two of them are still OK and the plus only need the 1st bank to boot

TFM

At the Wiki I can't find a decent picture of the Plus PCB, only GX4000. Can somebody give a pointer? Just asking, because it may help here.  :)
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

gerald

Quote from: TFM on 18:46, 17 June 16
At the Wiki I can't find a decent picture of the Plus PCB, only GX4000. Can somebody give a pointer? Just asking, because it may help here.  :)
what's wrong with these ?

TFM

Quote from: gerald on 19:01, 17 June 16
what's wrong with these ?

They are perfect!!! I will add a link to the Plus page, so people can find it. Thanks Gerald!  :) :) :)


EDIT: Done.
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

Bryce


keropi

Well, I hope it doesn't come to replacing the ASIC.... I have done some smaller pitch smd IC replacements in the past with my "good quality amateur equipment" (a 90eur weller soldering iron, quality flux, leaded solder - nothing special but nothing utterly crapish) but there were two important factors at play:
a. I could destroy the old IC (thus the pcb pads end up like nothing was ever soldered on them)
b. I had a brand new replacement IC


I am more than sure I can remove the old ASIC from my mobo and solder a replacement but I doubt I can successfully remove an ASIC from a donor board so that it won't have bent legs or heat damage with my current equipment. I do hope it doesn't come to this.


Atm all 4 ram ICs are removed and binned, sockets are soldered in their place and on Tuesday morning I will receive the loaner ram .
It is encouraging that with the dead ram onboard both the 74LS038s under it also became hot after a while but they test OK in my tester. The ASIC during that time didn't even come close to being hot so I do hope that the ram took all the stress... but there is no way of telling until the replacement ram arrives.


Oh the wait is killing me , like 9v on a 5v cpc  ;D ;D ;D

Bryce

The ASIC should be removed / soldered with hot air, not an iron. Get someone else to do it for you if it comes to that.

Bryce.

dragon

To the database, this guy fried the gx4000 with 11v in the 5v entrance.

Only ram and z80 die.

Repairing Console Amstrad GX4000 | nIGHTFALL Blog / RetroComputerMania.com

You probably maybe have lucky.

keropi

@Bryce
no guts no glory  :P


@dragon
good to have a little more hope, I got some Z80s here as well, they are the TOSHIBA ones though like TMPZ84C00AP-6 and TMPZ84C00AP-8




If the 6128+ ends up being fine I'll open a thread about scart cable / non-amstrad monitor connection. With the help of a good friend I realized that using a TTL Sync as RGB-enable voltage is a really dirty thing that leads to image deterioration (especially on lcd panels) and TTL-luma isn't that great either ...  maybe someone has delved deeper into this , especially the ttl-luma output....

Duke

I think the z80 will be OK, when it can setup the crtc (screen shot).

chinnyhill10

Quote from: dragon on 21:47, 17 June 16
To the database, this guy fried the gx4000 with 11v in the 5v entrance.



Really really common. Killed at least 2 of mine like that.
--
ChinnyVision - Reviews Of Classic Games Using Original Hardware
chinnyhill10 - YouTube

Bryce


dragon

Quote from: chinnyhill10 on 22:08, 17 June 16

Really really common. Killed at least 2 of mine like that.

And the asic survive?.

Duke

Completely agree, use hot air as Bryce said, atleast to remove it. I would use hot air to put it back it on aswell, but you can get away with using an iron and plenty of flux :)

Quote from: Bryce on 09:57, 18 June 16
...and no ASIC if you butcher it with an iron! :D

Bryce.

keropi

well yeah, it's no brainer that you need a hot air station to remove a smd IC like the ASIC in order to trsansplant it afterwards.
I never said I could remove a working ASIC and then transplant it using only my soldering iron for both tasks, that would be quite impossible  :D 

Duke

Good :)

Just replaced the ram on my cpc6128 that got 12V (grey screen of death) and it's fully working again. Only thing damaged was the RAM, hopefully you have same luck.
The RAM chips I got were V53C256P80L (41256) so just had gnd pin 1 (A8). This was regular CPC of course, not a plus.

TFM

Didn't the guy who made the JustCPC once tell that he has an internet source for ASICs? Forgot his name, but can't hurt to get in touch with him - just in worst case scenario.
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

gerald

Quote from: TFM on 17:27, 20 June 16
Didn't the guy who made the JustCPC once tell that he has an internet source for ASICs? Forgot his name, but can't hurt to get in touch with him - just in worst case scenario.
Yes he (Piotr) said that he has a source. But that's all he said  ;D

Bryce

And he was probably talking about Dönberg too.

Bryce.

dragon

Should be more easy buy the rights to amstrad. Take the tapes from steve gane, and made a fpga that find one new.lol.

keropi

Time to update the topic, I just got the RAM ICs and gave the machine a quick test: it works fine  ;D








Luckily it was only the RAM that failed (don't know if it was only one or two all ICs, I just replaced them all) and it seems everything went back to normal.

Thank you all for your support, input and help!

robcfg


1024MAK

Looking forward to summer in Somerset :-)

||C|-|E||

Congratulations! It seems that the electrolytic capacitors in that Plus have been replaced as well  :laugh: and there is an extra red wire next to the LED connector, and probably an ABBA switch too somewhere, right?  :D

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