Sharp HT-M700 DVD player - need help with pickup not driven...
Inserting disks you obtain "READING" message for a long time. Then "NO
DISK". Inside inspection (as per FAQ): the spindle motor correctly runs. Sled doesn't move unless you manually move it to a different location; it correctly comes back to the original position. It is correctly driven. Neither attempt to focus nor laser light up are performed (dead pickup). Removed/cleaned/remounted the pickup flat cable: no change. The lens servo works if manually powered (lens goes up and down) The laser lights up if manually powered. Power supply voltages are as per onboard indications. Seems a problem with the pickup driver circuitry. I published a snapshot of the main board @ http://www.qsl.net/iw1dhi/pickup-driver.JPG. Any idea about what to check further? Any information about test points? Any picofuse around?? Thanks in advance. Emanuele. |
Sharp HT-M700 DVD player - need help with pickup not driven...
On 1 Ott, 23:46, Emanuele Girlando
wrote: Inserting disks you obtain "READING" message for a long time. Then "NO DISK". Inside inspection (as per FAQ): the spindle motor correctly runs. Sled doesn't move unless you manually move it to a different location; it correctly comes back to the original position. It is correctly driven. Neither attempt to focus nor laser light up are performed (dead pickup). Removed/cleaned/remounted the pickup flat cable: no change. The lens servo works if manually powered (lens goes up and down) The laser lights up if manually powered. Power supply voltages are as per onboard indications. Seems a problem with the pickup driver circuitry. I published a snapshot of the main board @http://www.qsl.net/iw1dhi/pickup-driver.JPG. Any idea about what to check further? Any information about test points? Any picofuse around?? Thanks in advance. Emanuele. nobody out there ?? |
Sharp HT-M700 DVD player - need help with pickup not driven...
On Mon, 01 Oct 2007 14:46:54 -0700, Emanuele Girlando
put finger to keyboard and composed: Inserting disks you obtain "READING" message for a long time. Then "NO DISK". Inside inspection (as per FAQ): the spindle motor correctly runs. Sled doesn't move unless you manually move it to a different location; it correctly comes back to the original position. It is correctly driven. Neither attempt to focus nor laser light up are performed (dead pickup). Removed/cleaned/remounted the pickup flat cable: no change. The lens servo works if manually powered (lens goes up and down) The laser lights up if manually powered. Power supply voltages are as per onboard indications. Seems a problem with the pickup driver circuitry. I published a snapshot of the main board @ http://www.qsl.net/iw1dhi/pickup-driver.JPG. Any idea about what to check further? Any information about test points? Any picofuse around?? Thanks in advance. Emanuele. I don't know anything about your model, but I'd check the AM5868S driver IC. There is an application circuit in this datasheet: http://www.amtek-semi.com/files/AM5868.pdf Verify the inputs coming from the uP and check Vcc1 and Vcc2. I'd also look for a tray-in/tray-out switch at one of the connectors. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
Sharp HT-M700 DVD player - need help with pickup not driven...
On 5 Ott, 23:15, Franc Zabkar wrote:
On Mon, 01 Oct 2007 14:46:54 -0700, Emanuele Girlando put finger to keyboard and composed: Inserting disks you obtain "READING" message for a long time. Then "NO DISK". Inside inspection (as per FAQ): the spindle motor correctly runs. Sled doesn't move unless you manually move it to a different location; it correctly comes back to the original position. It is correctly driven. Neither attempt to focus nor laser light up are performed (dead pickup). Removed/cleaned/remounted the pickup flat cable: no change. The lens servo works if manually powered (lens goes up and down) The laser lights up if manually powered. Power supply voltages are as per onboard indications. Seems a problem with the pickup driver circuitry. I published a snapshot of the main board @http://www.qsl.net/iw1dhi/pickup-driver.JPG. Any idea about what to check further? Any information about test points? Any picofuse around?? Thanks in advance. Emanuele. I don't know anything about your model, but I'd check the AM5868S driver IC. There is an application circuit in this datasheet: http://www.amtek-semi.com/files/AM5868.pdf Verify the inputs coming from the uP and check Vcc1 and Vcc2. I'd also look for a tray-in/tray-out switch at one of the connectors. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. Franc, Vcc1 and Vcc2 are both at 5V. Specs call for +12V at pin8 (Vcc1) ... but it is connected to power supply +5V .. so I assume it is correct. Mute (pin28) is down to 0.37V in normal conditions. It rises at +2.2V during attempts to read disks. Sounds good. I'll further investigate tomorrow. Thank you very much for your support. |
All times are GMT +1. The time now is 03:06 PM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter