Corrosion on MB = No Calendar and No P1 Controller

All your console related questions and answers :)
Post Reply
User avatar
yo1dog
Posts: 13
Joined: Sun Jul 03, 2022 8:31 pm
Contact:

Corrosion on MB = No Calendar and No P1 Controller

Post by yo1dog » Sun Jul 03, 2022 9:09 pm

Calendar settings would never keep even after replacing the battery. I found a lot of corrosion on the MB next to the controller board ribbon cable. Clearly someone had spilling something on the GC long ago. I hit it with some isopropyl alcohol and a toothbrush.

Here's before and after:
Image Image


This seems to have caused R16 and C169 to break off. Now P1 controller port no longer works (P2, 3, and 4 do work).

Research revealed R16 is responsible for something to do with the battery and the clock/calendar settings. It was so corroded I assume that explains my initial issue. I also assume C169 is causing my controller issue.

Do you agree with my assumptions?
Does anyone have the specs for C169? I found R16 is 120ohm, but didn't find any schematics for the GC.
Recommendations on cleaning the remaining corrosion and rust?

I am electronics noob so, please, be gentle.

Thanks,
- Mike
Last edited by yo1dog on Sun Jul 17, 2022 10:46 pm, edited 2 times in total.
User avatar
yo1dog
Posts: 13
Joined: Sun Jul 03, 2022 8:31 pm
Contact:

Re: Corrosion on MB = No Calendar and No P1 Controller

Post by yo1dog » Sun Jul 03, 2022 9:37 pm

Actually, looks like C169 is not supposed to be there... Hard to find a good image of the motherboard but I found this:

https://github.com/webhdx/PicoBoot/blob ... g?raw=true
User avatar
Extrems
Posts: 1312
Joined: Tue Aug 17, 2010 10:40 pm
Location: Québec, Canada
Contact:

Re: Corrosion on MB = No Calendar and No P1 Controller

Post by Extrems » Sun Jul 03, 2022 10:36 pm

Yeah, the original schematic says it's not populated.
novenary
Posts: 1754
Joined: Mon Dec 30, 2013 7:50 am

Re: Corrosion on MB = No Calendar and No P1 Controller

Post by novenary » Mon Jul 04, 2022 2:30 pm

Short of using an ultrasonic cleaner, more scrubbing with a toothbrush or a q tip would be your best bet. You'll also want to rework those solder joints a bit (use flux liberally).
User avatar
yo1dog
Posts: 13
Joined: Sun Jul 03, 2022 8:31 pm
Contact:

Re: Corrosion on MB = No Calendar and No P1 Controller

Post by yo1dog » Tue Jul 05, 2022 8:24 am

Fixed it! Funny enough, the problem had nothing to do with that big mess. It was the ribbon cable.

It just hit me that I remembered seeing slight discoloration on one of the ribbon traces. I found more corrosion in the ribbon connector. Cleaned that out and it works again.

Now to get my EE brother-in-law to replace that tiny 0402 resistor for me.
User avatar
yo1dog
Posts: 13
Joined: Sun Jul 03, 2022 8:31 pm
Contact:

Re: Corrosion on MB = No Calendar and No P1 Controller

Post by yo1dog » Sun Jul 17, 2022 10:42 pm

TL;DR:
C162 had gone bad as well. Removed it. Does anyone know the capacitance of C162?
The ribbon cable connector leg for the V+ trace was destroyed. I bypassed it by connecting directly to battery terminal.
Used through-hole instead of SMD to replace R16. Soldered directly to IPL chip.
Need to attach C162 replacement between resistor and ground.
-----

It's been quite a journey, but I think I have it fixed. Thanks in large part to this post by dilav and help from my brother-in-law.

First, we realized that the left-most leg of the ribbon cable was also destroyed by the corrosion. This connects V+ from the battery on the controller board. Failing to "fix" the leg by flooding the gap with solder, I decided to just connect directly to the battery terminal.
Image Image

Then, being unable to solder the tiny 0402 footprint, I instead used a 120ohm through-hole resistor to replace R16... At least, I would have except I did not have any on hand so I used 6 of the 100ohm I did have. It's temporary I promise!
Image

I connected one end to edge of C162 and the other to the V+ battery terminal on the controller board. This worked! For a few hours... The next day the calendar was broken again. The battery measured 0.22 volts...
Image Image

V+ was shorted to ground causing the battery to drain quickly. I started mapping out traces looking for short.
Image Image

I found that C162 measured only 5ohms across. Clearly that cap was also killed by the corrosion and causing the short. I removed C162 and this time attached the resistor directly to the IPL chip (this was much easier than soldering to edge of SMD).
Image

Success! No more short to ground and calendar is still working days later.

I still need to replace C162. Should be easy to attach a through-hole cap between resistor and ground. Does anyone know the capacitance?
Last edited by yo1dog on Sun Jul 17, 2022 11:17 pm, edited 1 time in total.
User avatar
Extrems
Posts: 1312
Joined: Tue Aug 17, 2010 10:40 pm
Location: Québec, Canada
Contact:

Re: Corrosion on MB = No Calendar and No P1 Controller

Post by Extrems » Sun Jul 17, 2022 11:05 pm

1μF, 10V.
User avatar
yo1dog
Posts: 13
Joined: Sun Jul 03, 2022 8:31 pm
Contact:

Re: Corrosion on MB = No Calendar and No P1 Controller

Post by yo1dog » Sun Jul 17, 2022 11:18 pm

Extrems wrote:
Sun Jul 17, 2022 11:05 pm
1μF, 10V.
Thanks! Much appreciated.
Post Reply