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dvrtiger

Avtech AVC 773/776/777 date/time issue repair tips

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Recently I've got a truck load of AVC 773/776/777 DVRs in our service shop with the same symptoms: time/date issues and recording issues. The origin of this issues was tracked to back up capacitor, marked BT1 on PCB, which has the same purpose as a normal button cell battery on most DVRs. It is a 0.22uF/5.5V capacitor which you have to replace because it degrades it's capacitance by age. Also, you have to raplace two nearby crystal oscillators, marked X2 (22.1186kHz) near master microcontroller and X3 (32.768kHz) which are affected by degraded capacitor and it's leaking current.

I hope this will help to someone.

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No, I didn't notice that it's an issue related with some particular year of manufacture...to me, it is just a normal problem caused by a capacitor on such a critical position, which doesn't allow much of a tolerance, after some time.

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Hi

I'm having the same problem with three avc782zc dvr units that i have. Are those components suitable for and would replacing these components fix these units?

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Well, you have to look around clock oscillator and figure out if there is backup capacitor or battery, because I don't have knowledge about PCB setup on your models. But as I know, most AVC DVRs use the same crystals so the only difference would be between capacitor and battery.

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Hi dvrtiger. I just gor back from a break away.

 

The AV-782M dvrs i have do have a MS621 Surface Mount MS621FE Rechargeable Backup Battery located on the other side of the motherboard. I've never seen this on any electronics board before.

 

 

 

Can i simply replace this battery? could i even replace it with a standard CR2032 Rechargeable Backup Battery (found in most computer motherboards) which i have loads of laying around?

http://www.smallbattery.company.org.uk/sbc_cr2032-wr.htm

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796841028_AV-782MDVRBattery001.jpg.bb7d8648df29d2b7c4ebce41efd41902.jpg

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