|
|
Edited by cranwell at 2021-7-19 08:40
U12_6 on schematic, U908 on board, KA78R05 is running at 245 deg F (Almmost max allowable temp). Scope does not pass self callibration. stops step 2/38 0Xc00.
The large IC will fry the adjacent capacitors. 5V measures 4.98 at TP901. TP901 mjeasures 8 Ohms to Ground. Input to the IC is 13.5 V
Lifting the output of U908 (Pin 2) the buss resistance to ground is still 8 ohms and the IC does not overheat.
How hot should IC get during operation ? The spec sheet specifies Max 1.5W w/o heatsinc. The device is dissipating 5W from my calculations.
Should the BUSS be passing 625 Ma ? (5/8)
Any ideas to troubleshoot ?
|
|
Post time 2021-7-18 18:40:57
Favorites
Shares
Collection