----- Original Message ----- 
From: "James Alston" <jamesa@jpacsoft.com>
Subject: [PIC:] Can't reprogram 16LF819 in-circuit


> I have desoldered all the peripherals components in case they were causing
> the trouble. So now the only connections to the Vpp, PGC and PGD pins are
> from the board's programming header, but the reprogramming still fails.

 Is PGM (pin 9) still pulled low?

> Checking the signals on a scope: Vdd is 5V (if powered from the ICD2) or
> 3.3V (if powered from the board); During programming Vpp reaches 13.5V
(rise
> time of 70ns approx); PGC and PGD both produce good squarewaves between 0V
> and Vdd.

Does Vpp start well below 1 volt?

--McD



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