opening the drive door/lid of an RM03 ?

Hello readers, I cleaned the first of my RM03 drives today. The drive is quite clean even after several years of no attention. Just a few spiders webs and tiny dead spiders, and little dust. I picked up this drive in Turin Italy, together with Edward several years ago. I cannot remember doing it, but the head lock pin was in the lock position. After cleaning and a good inspection (I found a small metal bracket piece next to the PSU output plugs, and have not found where it came from!), I mounted a mains power plug to the drive cable. Massbus cable is attached to the drive, the other end is not connected to anything. After setting all circuit breakers ON (two inside the drive, two at the rear side next to the running hours counter), I plugged the mains in and switched mains on. I hear humming of the fans, so it seems OK. However, this is my problem: the door latch stays locked, I cannot open the lid. I want to open the lid to clean the inside of the drive bay. After some reading (EK-RM023-TD-001_RM02_03_Tech_May78.pdf), I found this in chapter 4.4 (page 4-7): The initialize sequence starts with the receipt of a Massbus INIT signal from either port A or B. This sequence is used to condition both the adapter and drive circuits to a known reset state. The functional block diagram for the initialize command is shown in Figure 4-5. The Massbus INIT signal (whether coming from port A or B) clears the AT A bit in the attention summary register in the IF module. In the CS module, it is converted to the MBA clear signal which performs the following: 1. Clears the enable search latch 2. Sets the on latch 3. etc. So, do I understand this correctly that without an initial Massbus INIT signal the lid remains locked? Or has this RM03 drive a "lock issue"? If somebody has an RM03 drive, is it possible to open the lid without Massbus cables hooked to the RH70 or RH11 controller? Is that Massbus connection required + INIT command to unlock the lid? I have not yet cleaned the other two RM03 drives, and I do not want to apply power without cleaning and inspection! So, I cannot check whether all 3 drives keep the lid locked. I forgot to take the camera with me, but I will take pictures! Thanks, - Henk