Post by thread:[PIC]: PicStart programming troubles on 'F877s

I am starting to get programming fails on PIC16F877s when it hasn't happened before. I have tested it on F872s (28 pin) on read and write. The PICSTART seems to be able to read the devices just fine but it doesn't seem to program an F877 properly, it gets a failure notice in MPLAB. Has anyone seen this before? Thanks! Jeff -- http://www.piclist.com hint: To leave the PICList spam_OUTpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

Check the power supply for the picstart. It may be failing (check the archives for similar messages). The archives will give you an idea of how to repair the PS, it generally means failed caps. You might also make sure you're using the latest firmware and software. Since it was working before you might have limited success, but it's worth a shot. -Adam Jeff DeMaagd wrote: {Quote hidden}>I am starting to get programming fails on PIC16F877s when it hasn't >happened before. > >I have tested it on F872s (28 pin) on read and write. The PICSTART >seems to be able to read the devices just fine but it doesn't seem to >program an F877 properly, it gets a failure notice in MPLAB. > >Has anyone seen this before? > >Thanks! > >Jeff > >-- >http://www.piclist.com hint: To leave the PICList >.....piclist-unsubscribe-requestKILLspam@spam@mitvma.mit.edu > > > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Jeff DeMaagd wrote: > > I am starting to get programming fails on PIC16F877s when it hasn't > happened before. > > I have tested it on F872s (28 pin) on read and write. The PICSTART > seems to be able to read the devices just fine but it doesn't seem to > program an F877 properly, it gets a failure notice in MPLAB. > > Has anyone seen this before? YES! Replace the 3 small electro caps in the PSU brick. And DON'T leave it plugged in, heat kills it and the cheap nasty thing doesn't have an on/off switch... -Roman -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Thanks, but I think I have fried the chips somehow in a particular test circuit where I connected two of them together to try to get the Parallel Slave Port system going, one programmed to play master and the other programmed to play slave, but it didn't work as well as I'd like. I have found a third 'F877 that programs and verifies just fine. Jeff {Original Message removed}

OK, maybe not, maybe the power supply is toast. It reads 12.6VDC, little to no ripple at no load and when programming the PS reads 11.3VDC with 0.17VAC ripple, when the package says 9VDC. I didn't find anything about PS caps, the piclist site has a page about "wallwarts" and a non-wallwart power supply, and it says that it really needs 9VDC to work, much more won't work properly. I have a wallwart and the thing is sealed, I don't see a way to replace caps without breaking the case. Suggestions? I tried the archives but nothing relevant seems to come up with any permutation of these key words: picstart plus capacitor replacement power supply problem Jeff {Original Message removed}