Biggles - 24 minutes ago »
Hi Martin, just to confirm, I believe MS_Boffin is saying this blinking display happened with the 9200 switched ON?
That is correct and exactly what I saw. Blinking clock whilst on was a prelude to clock failure in standby which at first was intermittent and then became permanent.
OK thanks, so that indicates MS_Boffin simply has the clock problem with no other complications.
Thanks for all the input and confirmation of my clock problem. I'm seeing similar intermittent problems this evening. No repeat of the blinking clock yet (yes, it was in operate at the time) but sometimes the clock is blank in standby - sometimes it displays correctly.
I am armed with cotton buds, white board cleaner (100% iso-propanol) and surgical spirit. Just going to print off the cleaning instructions and I will get the board cleaned tonight.
MS_Boffin
Don't forget the little brush to get into the awkward places. I was looking on the Superdrug website the other day and it said their surgical spirit contained caster oil for softening hard skin, nice! Probably make the clock operation very slick. 
I discovered that the surgical spirit I bought from Tesco pharmacy was not pure ethanol and also had oils added to it :-(. I didn't use it and went ahead with the cleaning using the iso-propanol.
Taking the board out was straight forward and I didn't need any instructions for that part.
I followed the cleaning instructions and removed quit a lot of yellow / brown residue from the back of the board using three cotton buds. The fourth bud had no obvious dirt on it so I moved to the front of the board. I suggest adding a magnifying glass to the tools list. At least for my old eyes, I needed magnification to be able to see the component labels clearly. On my board, the crystal was labelled Y901 rather than Y921. At first I thought the super capacitor had leaked; there was some white material underneath it. On closer inspection I think this may be heatsink compound distributing heat to a small copper pad under the body of the capacitor. I used a small brush with quite stiff bristles (I think it was intended to be a stencil brush for small detail work). I found it easier than using cotton buds where strands of cotton would snag on the solder joints. The stiff bristles easily got between the pins of the chip etc without causing damage. After applying the cleaning fluid, blotting the brush on tissue dries the brush so that it can then be used to remove excess fluid from the board. I repeated that process 3 times as well. I took a few pictures of the front & back of the board and close ups the timing circuit components. It wasn't easy to get the lighting right but they might be useful to orient others to the correct area for cleaning.
Finally getting to the point. Did it work? Well, given the intermittent behaviour I've seen it's a bit early to say for sure BUT I have not seen a blank clock display since I put it all back together (3 hours ago) and I have recorded from standby for the first time in 6 or 8 weeks. So I'm almost ready to say it's fixed. I have scheduled a few recording events for tomorrow as a more comprehensive test and will report back.... but I am very optimistic.
Thanks for all your help! It is amazing to me to find such a helpful forum with posts from real experts - for a device that ceased production years ago. How are you at diagnosing Land Rover transmission faults?
MS_Boffin
MS_Boffin - 5 minutes ago »
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I took a few pictures of the front & back of the board and close ups the timing circuit components. It wasn't easy to get the lighting right but they might be useful to orient others to the correct area for cleaning.
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MS_Boffin
Hmmmm. Looks like the photos are too big to upload. If anyone is interested I can reduce the quality and re-post.
MS_Boffin
If it's not too much trouble MS Boffin some pics would be helpful
MS_Boffin - 5 hours ago »
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At first I thought the super capacitor had leaked; there was some white material underneath it. On closer inspection I think this may be heatsink compound distributing heat to a small copper pad under the body of the capacitor.
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MS_Boffin
Unlikely to be heat sink compound as there is no significant heat generated in this circuit to require it.
There was no mention of oils in the surgical spirit I saw in Boots, obviously different manufacturers put in there own additives, I think they would all work satisfactorily though. Sorry can't help with the Land Rover.
All the recordings worked ok and i have only seen correct clock behaviour since cleaning so I think its fixed!!
Considering the help I got here, no problem at all to post the pics. I need to make some lower quality images first. Anyone know the file size limit for uploads?
MS_Boffin
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