Posts tagged ‘repair’

FT991 IPO/ATT FAULT

Yaesu FT-991A Frontend has nasty hidden fault. It is not normal from €1000 radio to stop working just because you use it in a pileup situation or when your close OM is beaming toward you with QRO.

New, out-of-the box radio receive performance of the FT-991(A) was normal, but after other station(s) had transmitted at a higher power levels, the FT-991(A) receiver failed. The failure mode was as follows:

  • Receiver operation is normal when the Attenuator feature is disabled.
  • Receiver operation fails (no receive and a very quiet noise-floor) when the Attenuator feature is enabled.
  • IPO operation enables the Attenuator and results in the same receiver failure mentioned immediately above.

Same issues are reported elsewhere:

Patient with exactly the same simptoms got to the operation table in my lab today. The owner is OM S52W, very successfull contester and member of the famous contest club.

Continue reading ‘FT991 IPO/ATT FAULT’ »

Archos tablet 10.1 repair

My Archos 10.1 died. The death was not sudden. At first, the charging was slower, after a while I noticed “blink blink problem“. After few days the tablet turned int a brick. I realised it was the time for some action…

Opening Archos 10.1  is fairly simple. There are 6 small torx srews and dozen of plastic clips around the case holding both sides together. To separate plastic parts use your nails or similar “material”, which is softer than plastics to avoid scratches. There is plastic lid covering all side connectors. Camera is within rubber holder and MIC has one rubber cover. Remove all tiny parts into safe place.

Two flex capton foils connects LCD side with periphery. Wider has dual row connector and narrower, 4 pin ribbon (probably the touch controller) has small connector. Remove orange adhesive tapes and pull the wider ribb on out from the board. Open the small connector (black part up!) and pull out the ribbon. Now warm up your soldering iron and unsolder the battery from the circuit (red B+ wire) to avoid “escaping smoke” effects. Isolate the red wire with some isolation! Continue reading ‘Archos tablet 10.1 repair’ »