Radio Make and Model: TRC-1015 re-badged Maycom AH-27
PCB Number: M40E067B 98.07.16
PLL Number:
Test gear available: Just about everything.
Symptoms: Burnt out diode and transistor/diode?
Hi,
Picked up a couple of faulty re-badged AH-27's with the same problem in that there has been a burn out of two components on the CPU board. One is repairable but the other, the board is badly charred.
One of the components is labelled AA7M and there is another one on the board. It looks like a diode but I'm not sure?
The other device was 3 legged but not a transistor as the two outside pads were connected together. These were totally destroyed on both boards.
I've hopefully attached a jpeg to show this (devices already removed).
Now, my problem is the diagram I have for the AH27 doesn't appear to match the PCB?? As there are no silk screen markings on the component side I can't work out what these components should be.
Service manuals appear to be non existent so I'm stuck.
Any pointers?
Cheers
Midbob
Maycom AH-27
Maycom AH-27
- Attachments
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- ah-27_pcb.JPG (144.42 KiB) Viewed 5309 times
Re: Maycom AH-27
Hope someone finds this useful.
After many hours of re-reading the diagram it became apparent that the component marked AA7M was actually a 10uF capacitor (C920). The semiconductor device was a diode (D936) but the diagram part number wasn't listed as an SMD manufactured component?
Anyway, I managed to salvage some parts from a scrap PSU board and repaired both units. On one unit parts of the track were burnt and the board was almost burnt through. Scraping out the carbon and filling with epoxy then salvaging some track from the PSU board resulted in success. It's amazing what you can do with a microscope and a steady hand.
If anyone does have a service manual for this model I'd love a copy of it.
Midibob
After many hours of re-reading the diagram it became apparent that the component marked AA7M was actually a 10uF capacitor (C920). The semiconductor device was a diode (D936) but the diagram part number wasn't listed as an SMD manufactured component?
Anyway, I managed to salvage some parts from a scrap PSU board and repaired both units. On one unit parts of the track were burnt and the board was almost burnt through. Scraping out the carbon and filling with epoxy then salvaging some track from the PSU board resulted in success. It's amazing what you can do with a microscope and a steady hand.
If anyone does have a service manual for this model I'd love a copy of it.
Midibob