is part of the manual is very useful for repairing
Here are circuit diagrams
if there is damage, I recommend using this part of the
a complete list of circuit boards and components
ecelent I was reciver the service manual soon I fell so happy very complete 100% positive all by this store tanks atte Luis salazar
Text excerpt from page 26 (click to view)
10. TROUBLESHOOTING
1. Intermittent display START Y Is the Heat seal defective ? N Y Is the battery contact weak ? N Are there short circuit around the pins Y of the LSI (HC3000-08-F1) ? N Is the soldering weak ? Y N Replace the Z808-1 PCB ass'y. Replace Clean and adjust pressure of contact Resolder Resolder
2.
Erratic display START Is the Heat seal defective ? N Is the LCD defective ? Y Y Replace Replace Check or replace the chip capacitors C4 ~ C8 Y Resolder
N N Are the voltage V0 ~ V4 OK ? Y Are there short circuit around the pins of the LSI (HC3000-08-F1) or between the pins of the crystal oscillator (·2) ? N Are there short circuit around the pins of the RAM and ROM ? N Replace the Z808-1 PCB ass'y.