Nava don´t works, help. Microcontroller problem?

Discuss Nava construction and related issues
  • User avatar
    KlangGenerator
    Posts 371
    Joined: Aug 8th, '16, 16:36

    Sounds to me like IC115 is the problem. Try replacing it. Display adjustment is done with TM3. Also take out the resistor at R694 and put in a wire instead. The display has a resitor built in for the backlight, so the 1.2k one in R694 causes it to be too dark.

    IMPORTANT: Always turn off your Nava when doing any changes or touching the board. Otherwise you run a high risk to damage components, especially ICs!
  • Huertos
    Posts 7
    Joined: Jan 24th, '17, 08:03

    Hi Klang. I´ll try with replacing the ic115. I did the display adjustment in TM3, If i trim to máximum position I can see the red squares for the letters but any letter, so do you mean I need change the value of R694.

    Thankyou verymuch in advance
  • User avatar
    KlangGenerator
    Posts 371
    Joined: Aug 8th, '16, 16:36

    If you can't see anything then the issue is somewhere else. With the 1.2k implemented the light is just more dim. But try replacing IC115 first. I am very sure this is the reason why your display is dark... ;)
    Last edited by KlangGenerator on Mar 16th, '17, 15:23, edited 1 time in total.
  • 4teenth
    Posts 195
    Joined: Jan 16th, '14, 01:51

    Sorry to hijack, but do you reckon my problem could be IC115 too?

    viewtopic.php?f=24&t=1093
  • User avatar
    KlangGenerator
    Posts 371
    Joined: Aug 8th, '16, 16:36

    4teenth wrote:Sorry to hijack, but do you reckon my problem could be IC115 too?

    viewtopic.php?f=24&t=1093
    No, I don't think this relies on a faulty IC115. Sounds more to me like you destroyed the LCD when trying to desoldering it. Use something like this next time you want to do complex desoldering work: http://komerci.de/shop/product_info.php ... 4d85e36d4a Really not that expensive and it is really easy to use. I recently desoldered 7 ICs with this tool in under 5 minutes on a Nava sequencer! https://www.youtube.com/watch?v=v0iA_b0WTDg
  • 4teenth
    Posts 195
    Joined: Jan 16th, '14, 01:51

    I assumed the LCD was toast, so I replaced it with a band new one rather than risk using the old one.

    That looks like a nice desoldering tool though, I might check that out - I've been getting by with a cheap heated tool with solenoid pump type deal, which was a step up from the heated tool with manual spring pump, but still nowhere as nice or quick as that one. And seeing as I have another TTSH kit to put together, and a Jasper Wasp clone it might be a worthy purchase... :)
  • Huertos
    Posts 7
    Joined: Jan 24th, '17, 08:03

    Hello everybody. I replaced the ic115 and no way. The problem still there, sequencer not running, no characters on the display so any sound. I replaced the ic115 with this two kinds of semiconductors
    http://eu.mouser.com/ProductDetail/ON-S ... 6aiLsuk%3d
    http://eu.mouser.com/ProductDetail/Micr ... WI51o17Dff

    Could be the atmga is not properly flashed? I cheked all the pcb , voltajes... everything seems to be ok.
  • lukep_gdansk
    Posts 105
    Joined: Dec 22nd, '16, 17:04

    Yes, it is possible that Atmega is dead.
  • User avatar
    KlangGenerator
    Posts 371
    Joined: Aug 8th, '16, 16:36

    Huertos wrote:Hello everybody. I replaced the ic115 and no way. The problem still there, sequencer not running, no characters on the display so any sound. I replaced the ic115 with this two kinds of semiconductors
    http://eu.mouser.com/ProductDetail/ON-S ... 6aiLsuk%3d
    http://eu.mouser.com/ProductDetail/Micr ... WI51o17Dff

    Could be the atmga is not properly flashed? I cheked all the pcb , voltajes... everything seems to be ok.
    Did you do a complete reset? Press "start" and "stop" when powering up, then initialize eeprom by pressing "start' and "enter". Also did you adjust "tm3" for display contrast?
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